Match blur system and method
View Patent ↗A method for blurring in signal processing, for example, in digital film processing, is performed with digital artifacts. The digital artifacts are derived, such as by scanning, and include a noisy artifact and a less noisy artifact. The artifacts are subdivided into a plurality of windows, with each window being subdivided into a plurality of squares. The squares of the noisy artifact and of the less noisy artifact have spatial correspondence, as do the respective windows. The method includes determining a difference between a square at a centrum of a window of the less noisy artifact and another square within the window of the less noisy artifact, weighting a value for the square based on the difference, summing all of the values for the square as so weighted, multiplying a value for the square of the window of the noisy artifact by the result of summing, summing all of the results of multiplying for each square of the window of the noisy artifact, and dividing the result of summing all of the results, by the result of summing all of the values for the square. The method can also include multiplying certain values by a percentage to limit over-expression of certain properties exhibited in certain of the artifacts, for example, magenta mottle.
1. A subroutine in a method of blurring, said subroutine comprising the steps of:
deriving a noisy artifact exhibiting a color green;
selecting a less noisy artifact exhibiting a color green;
subdividing the noisy artifact into a plurality of windows;
subdividing each of the plurality of windows into a plurality of squares;
subdividing the less noisy artifact into a plurality of windows corresponding to the plurality of windows of the noisy artifact;
subdividing each of the plurality of windows of the less noisy artifact into a plurality of squares corresponding to the plurality of squares of the noisy artifact;
determining a difference between a square at a centrum of a window of the less noisy artifact and all of the other squares within the window of the less noisy artifact;
weighting the difference between a square at a centrum of a window of the less noisy artifact and said other squares by multiplying the difference by a multiplying factor;
varying the step of weighting by (a) 75% for the square of the window of the noisy artifact which is less than the square at the centrum of the window of the noisy artifact and (b) 25% for each square of the window of the noisy artifact which is not less than the square at the centrum of the window of the noisy artifact;
summing all of the values for said other squares as so weighted;
multiplying a value for each one of said other squares of the window of the noisy artifact by results of the step of summing;
summing said results of the step of multiplying for each of said other squares of the window of the noisy artifact; and
dividing said results of the step of summing said results, by the result of the step of summing all of the values for said other squares.
2. The subroutine of claim 1 , further comprising the step of:
clamping the weighting step between minimum and maximum extremes, if the noisy artifact tends to be overly expressed in a result.
3. The subroutine of claim 1 , further comprising the step of:
clamping the step of weighting so that the weight for the value is in the range of 0 to 1.